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    <div class='section' id='section-0'>
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            <h3>Test Flash Attention Implementation</h3>
<p>This is the code to test and measure performance of our flash attention implementation</p>

        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">7</span><span></span><span class="kn">import</span> <span class="nn">torch</span>
<span class="lineno">8</span><span class="kn">import</span> <span class="nn">triton</span>
<span class="lineno">9</span>
<span class="lineno">10</span><span class="kn">from</span> <span class="nn">labml</span> <span class="kn">import</span> <span class="n">logger</span><span class="p">,</span> <span class="n">monit</span>
<span class="lineno">11</span><span class="kn">from</span> <span class="nn">labml_nn.transformers.flash</span> <span class="kn">import</span> <span class="n">attention</span>
<span class="lineno">12</span>
<span class="lineno">13</span><span class="n">HI_PRES_TORCH</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">float32</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-1'>
        <div class='docs doc-strings'>
            <div class='section-link'>
                <a href='#section-1'>#</a>
            </div>
            <h4>Calculate absolute and relative error for reporting</h4>

        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">16</span><span class="nd">@torch</span><span class="o">.</span><span class="n">no_grad</span><span class="p">()</span>
<span class="lineno">17</span><span class="k">def</span> <span class="nf">_calc_abs_rel_error</span><span class="p">(</span><span class="n">a</span><span class="p">:</span> <span class="n">torch</span><span class="o">.</span><span class="n">Tensor</span><span class="p">,</span> <span class="n">b</span><span class="p">:</span> <span class="n">torch</span><span class="o">.</span><span class="n">Tensor</span><span class="p">,</span> <span class="n">atol</span><span class="o">=</span><span class="mf">1e-2</span><span class="p">):</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-2'>
        <div class='docs'>
            <div class='section-link'>
                <a href='#section-2'>#</a>
            </div>
            
        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">21</span>    <span class="n">d</span> <span class="o">=</span> <span class="p">(</span><span class="n">a</span> <span class="o">-</span> <span class="n">b</span><span class="p">)</span><span class="o">.</span><span class="n">abs</span><span class="p">()</span>
<span class="lineno">22</span>    <span class="n">max_abs</span> <span class="o">=</span> <span class="n">d</span><span class="o">.</span><span class="n">max</span><span class="p">()</span>
<span class="lineno">23</span>    <span class="n">d</span> <span class="o">=</span> <span class="p">(</span><span class="n">d</span> <span class="o">-</span> <span class="n">atol</span><span class="p">)</span><span class="o">.</span><span class="n">clamp</span><span class="p">(</span><span class="nb">min</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="lineno">24</span>    <span class="n">d</span> <span class="o">=</span> <span class="n">d</span> <span class="o">/</span> <span class="n">b</span><span class="o">.</span><span class="n">abs</span><span class="p">()</span>
<span class="lineno">25</span>    <span class="n">max_rel</span> <span class="o">=</span> <span class="n">d</span><span class="o">.</span><span class="n">max</span><span class="p">()</span>
<span class="lineno">26</span>
<span class="lineno">27</span>    <span class="k">return</span> <span class="n">max_abs</span><span class="o">.</span><span class="n">cpu</span><span class="p">()</span><span class="o">.</span><span class="n">item</span><span class="p">(),</span> <span class="n">max_rel</span><span class="o">.</span><span class="n">cpu</span><span class="p">()</span><span class="o">.</span><span class="n">item</span><span class="p">()</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-3'>
        <div class='docs doc-strings'>
            <div class='section-link'>
                <a href='#section-3'>#</a>
            </div>
            <h4>Compare our implementation with naive PyTorch attention</h4>

        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">30</span><span class="k">def</span> <span class="nf">test_fwd_bwd</span><span class="p">(</span><span class="n">batch_size</span><span class="p">,</span> <span class="n">n_heads</span><span class="p">,</span> <span class="n">k_heads</span><span class="p">,</span> <span class="n">q_seq_len</span><span class="p">,</span> <span class="n">kv_seq_len</span><span class="p">,</span> <span class="n">d_head</span><span class="p">,</span> <span class="n">causal</span><span class="p">,</span> <span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="p">):</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-4'>
        <div class='docs'>
            <div class='section-link'>
                <a href='#section-4'>#</a>
            </div>
            
        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">35</span>    <span class="k">with</span> <span class="n">monit</span><span class="o">.</span><span class="n">section</span><span class="p">(</span><span class="sa">f</span><span class="s1">&#39;Init </span><span class="si">{</span><span class="n">q_seq_len</span><span class="si">}</span><span class="s1"> </span><span class="si">{</span><span class="n">kv_seq_len</span><span class="si">}</span><span class="s1"> </span><span class="si">{</span><span class="n">d_head</span><span class="si">}</span><span class="s1">&#39;</span><span class="p">):</span>
<span class="lineno">36</span>        <span class="n">torch</span><span class="o">.</span><span class="n">manual_seed</span><span class="p">(</span><span class="mi">20</span><span class="p">)</span>
<span class="lineno">37</span>        <span class="n">q</span> <span class="o">=</span> <span class="p">(</span><span class="n">torch</span><span class="o">.</span><span class="n">empty</span><span class="p">((</span><span class="n">batch_size</span><span class="p">,</span> <span class="n">n_heads</span><span class="p">,</span> <span class="n">q_seq_len</span><span class="p">,</span> <span class="n">d_head</span><span class="p">),</span>
<span class="lineno">38</span>                         <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">)</span><span class="o">.</span><span class="n">normal_</span><span class="p">(</span><span class="n">mean</span><span class="o">=</span><span class="mf">0.0</span><span class="p">,</span> <span class="n">std</span><span class="o">=</span><span class="mf">0.5</span><span class="p">)</span><span class="o">.</span><span class="n">requires_grad_</span><span class="p">())</span>
<span class="lineno">39</span>        <span class="n">k</span> <span class="o">=</span> <span class="p">(</span><span class="n">torch</span><span class="o">.</span><span class="n">empty</span><span class="p">((</span><span class="n">batch_size</span><span class="p">,</span> <span class="n">k_heads</span><span class="p">,</span> <span class="n">kv_seq_len</span><span class="p">,</span> <span class="n">d_head</span><span class="p">),</span>
<span class="lineno">40</span>                         <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">)</span><span class="o">.</span><span class="n">normal_</span><span class="p">(</span><span class="n">mean</span><span class="o">=</span><span class="mf">0.0</span><span class="p">,</span> <span class="n">std</span><span class="o">=</span><span class="mf">0.5</span><span class="p">)</span><span class="o">.</span><span class="n">requires_grad_</span><span class="p">())</span>
<span class="lineno">41</span>        <span class="n">v</span> <span class="o">=</span> <span class="p">(</span><span class="n">torch</span><span class="o">.</span><span class="n">empty</span><span class="p">((</span><span class="n">batch_size</span><span class="p">,</span> <span class="n">k_heads</span><span class="p">,</span> <span class="n">kv_seq_len</span><span class="p">,</span> <span class="n">d_head</span><span class="p">),</span>
<span class="lineno">42</span>                         <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">)</span><span class="o">.</span><span class="n">normal_</span><span class="p">(</span><span class="n">mean</span><span class="o">=</span><span class="mf">0.0</span><span class="p">,</span> <span class="n">std</span><span class="o">=</span><span class="mf">0.5</span><span class="p">)</span><span class="o">.</span><span class="n">requires_grad_</span><span class="p">())</span>
<span class="lineno">43</span>        <span class="n">sm_scale</span> <span class="o">=</span> <span class="n">d_head</span> <span class="o">**</span> <span class="o">-</span><span class="mf">0.5</span>
<span class="lineno">44</span>        <span class="n">d_out</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">randn_like</span><span class="p">(</span><span class="n">q</span><span class="p">)</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-5'>
        <div class='docs'>
            <div class='section-link'>
                <a href='#section-5'>#</a>
            </div>
            <p>reference implementation </p>

        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">46</span>        <span class="n">mask</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">tril</span><span class="p">(</span><span class="n">torch</span><span class="o">.</span><span class="n">ones</span><span class="p">((</span><span class="n">q_seq_len</span><span class="p">,</span> <span class="n">kv_seq_len</span><span class="p">),</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">torch</span><span class="o">.</span><span class="n">bool</span><span class="p">))</span>
<span class="lineno">47</span>        <span class="n">torch</span><span class="o">.</span><span class="n">cuda</span><span class="o">.</span><span class="n">synchronize</span><span class="p">()</span>
<span class="lineno">48</span>
<span class="lineno">49</span>    <span class="k">with</span> <span class="n">monit</span><span class="o">.</span><span class="n">section</span><span class="p">(</span><span class="s1">&#39;Pytorch&#39;</span><span class="p">):</span>
<span class="lineno">50</span>        <span class="n">p</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">matmul</span><span class="p">(</span><span class="n">q</span><span class="o">.</span><span class="n">view</span><span class="p">(</span><span class="n">batch_size</span><span class="p">,</span> <span class="n">k_heads</span><span class="p">,</span> <span class="o">-</span><span class="mi">1</span><span class="p">,</span> <span class="n">q_seq_len</span><span class="p">,</span> <span class="n">d_head</span><span class="p">),</span>
<span class="lineno">51</span>                         <span class="n">k</span><span class="o">.</span><span class="n">transpose</span><span class="p">(</span><span class="mi">2</span><span class="p">,</span> <span class="mi">3</span><span class="p">)[:,</span> <span class="p">:,</span> <span class="kc">None</span><span class="p">,</span> <span class="p">:,</span> <span class="p">:])</span> <span class="o">*</span> <span class="n">sm_scale</span>
<span class="lineno">52</span>        <span class="k">if</span> <span class="n">causal</span><span class="p">:</span>
<span class="lineno">53</span>            <span class="n">p</span><span class="p">[:,</span> <span class="p">:,</span> <span class="p">:,</span> <span class="o">~</span><span class="n">mask</span><span class="p">]</span> <span class="o">=</span> <span class="nb">float</span><span class="p">(</span><span class="s2">&quot;-inf&quot;</span><span class="p">)</span>
<span class="lineno">54</span>        <span class="n">p</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">softmax</span><span class="p">(</span><span class="n">p</span><span class="o">.</span><span class="n">to</span><span class="p">(</span><span class="n">HI_PRES_TORCH</span><span class="p">),</span> <span class="n">dim</span><span class="o">=-</span><span class="mi">1</span><span class="p">)</span><span class="o">.</span><span class="n">to</span><span class="p">(</span><span class="n">dtype</span><span class="p">)</span>
<span class="lineno">55</span>        <span class="n">ref_out</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">matmul</span><span class="p">(</span><span class="n">p</span><span class="p">,</span> <span class="n">v</span><span class="p">[:,</span> <span class="p">:,</span> <span class="kc">None</span><span class="p">,</span> <span class="p">:,</span> <span class="p">:])</span>
<span class="lineno">56</span>        <span class="n">ref_out</span> <span class="o">=</span> <span class="n">ref_out</span><span class="o">.</span><span class="n">view</span><span class="p">(</span><span class="n">q</span><span class="o">.</span><span class="n">shape</span><span class="p">)</span>
<span class="lineno">57</span>        <span class="n">ref_out</span><span class="o">.</span><span class="n">backward</span><span class="p">(</span><span class="n">d_out</span><span class="p">)</span>
<span class="lineno">58</span>        <span class="n">ref_dv</span><span class="p">,</span> <span class="n">v</span><span class="o">.</span><span class="n">grad</span> <span class="o">=</span> <span class="n">v</span><span class="o">.</span><span class="n">grad</span><span class="o">.</span><span class="n">clone</span><span class="p">(),</span> <span class="kc">None</span>
<span class="lineno">59</span>        <span class="n">ref_dk</span><span class="p">,</span> <span class="n">k</span><span class="o">.</span><span class="n">grad</span> <span class="o">=</span> <span class="n">k</span><span class="o">.</span><span class="n">grad</span><span class="o">.</span><span class="n">clone</span><span class="p">(),</span> <span class="kc">None</span>
<span class="lineno">60</span>        <span class="n">ref_dq</span><span class="p">,</span> <span class="n">q</span><span class="o">.</span><span class="n">grad</span> <span class="o">=</span> <span class="n">q</span><span class="o">.</span><span class="n">grad</span><span class="o">.</span><span class="n">clone</span><span class="p">(),</span> <span class="kc">None</span>
<span class="lineno">61</span>        <span class="n">torch</span><span class="o">.</span><span class="n">cuda</span><span class="o">.</span><span class="n">synchronize</span><span class="p">()</span>
<span class="lineno">62</span>
<span class="lineno">63</span>    <span class="k">with</span> <span class="n">monit</span><span class="o">.</span><span class="n">section</span><span class="p">(</span><span class="s1">&#39;Triton&#39;</span><span class="p">):</span>
<span class="lineno">64</span>        <span class="k">assert</span> <span class="n">q</span><span class="o">.</span><span class="n">dtype</span> <span class="o">==</span> <span class="n">dtype</span>
<span class="lineno">65</span>        <span class="n">tri_out</span> <span class="o">=</span> <span class="n">attention</span><span class="p">(</span><span class="n">q</span><span class="p">,</span> <span class="n">k</span><span class="p">,</span> <span class="n">v</span><span class="p">,</span> <span class="n">causal</span><span class="p">,</span> <span class="n">sm_scale</span><span class="p">)</span><span class="o">.</span><span class="n">to</span><span class="p">(</span><span class="n">dtype</span><span class="p">)</span>
<span class="lineno">66</span>        <span class="n">monit</span><span class="o">.</span><span class="n">progress</span><span class="p">(</span><span class="mf">0.5</span><span class="p">)</span>
<span class="lineno">67</span>
<span class="lineno">68</span>        <span class="n">tri_out</span><span class="o">.</span><span class="n">backward</span><span class="p">(</span><span class="n">d_out</span><span class="p">)</span>
<span class="lineno">69</span>        <span class="n">monit</span><span class="o">.</span><span class="n">progress</span><span class="p">(</span><span class="mf">0.9</span><span class="p">)</span>
<span class="lineno">70</span>        <span class="n">tri_dv</span><span class="p">,</span> <span class="n">v</span><span class="o">.</span><span class="n">grad</span> <span class="o">=</span> <span class="n">v</span><span class="o">.</span><span class="n">grad</span><span class="o">.</span><span class="n">clone</span><span class="p">(),</span> <span class="kc">None</span>  <span class="c1"># type: ignore</span>
<span class="lineno">71</span>        <span class="n">tri_dk</span><span class="p">,</span> <span class="n">k</span><span class="o">.</span><span class="n">grad</span> <span class="o">=</span> <span class="n">k</span><span class="o">.</span><span class="n">grad</span><span class="o">.</span><span class="n">clone</span><span class="p">(),</span> <span class="kc">None</span>  <span class="c1"># type: ignore</span>
<span class="lineno">72</span>        <span class="n">tri_dq</span><span class="p">,</span> <span class="n">q</span><span class="o">.</span><span class="n">grad</span> <span class="o">=</span> <span class="n">q</span><span class="o">.</span><span class="n">grad</span><span class="o">.</span><span class="n">clone</span><span class="p">(),</span> <span class="kc">None</span>  <span class="c1"># type: ignore</span>
<span class="lineno">73</span>        <span class="n">torch</span><span class="o">.</span><span class="n">cuda</span><span class="o">.</span><span class="n">synchronize</span><span class="p">()</span>
<span class="lineno">74</span>
<span class="lineno">75</span>    <span class="k">with</span> <span class="n">monit</span><span class="o">.</span><span class="n">section</span><span class="p">(</span><span class="s1">&#39;Test&#39;</span><span class="p">)</span> <span class="k">as</span> <span class="n">s</span><span class="p">:</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-6'>
        <div class='docs'>
            <div class='section-link'>
                <a href='#section-6'>#</a>
            </div>
            <p>compare </p>

        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">77</span>        <span class="n">passed</span> <span class="o">=</span> <span class="kc">True</span>
<span class="lineno">78</span>        <span class="k">if</span> <span class="ow">not</span> <span class="n">torch</span><span class="o">.</span><span class="n">allclose</span><span class="p">(</span><span class="n">tri_out</span><span class="p">,</span> <span class="n">ref_out</span><span class="p">,</span> <span class="n">atol</span><span class="o">=</span><span class="mf">1e-2</span><span class="p">,</span> <span class="n">rtol</span><span class="o">=</span><span class="mf">0.</span><span class="p">):</span>
<span class="lineno">79</span>            <span class="n">abs_err</span><span class="p">,</span> <span class="n">rel_err</span> <span class="o">=</span> <span class="n">_calc_abs_rel_error</span><span class="p">(</span><span class="n">ref_out</span><span class="p">,</span> <span class="n">tri_out</span><span class="p">)</span>
<span class="lineno">80</span>            <span class="n">logger</span><span class="o">.</span><span class="n">log</span><span class="p">((</span><span class="s1">&#39;[FAILED]&#39;</span><span class="p">,</span> <span class="n">logger</span><span class="o">.</span><span class="n">Text</span><span class="o">.</span><span class="n">danger</span><span class="p">),</span> <span class="sa">f</span><span class="s1">&#39; Out mismatch </span><span class="si">{</span><span class="n">abs_err</span><span class="si">}</span><span class="s1"> </span><span class="si">{</span><span class="n">rel_err</span><span class="si">}</span><span class="s1">&#39;</span><span class="p">)</span>
<span class="lineno">81</span>            <span class="n">passed</span> <span class="o">=</span> <span class="kc">False</span>
<span class="lineno">82</span>        <span class="n">rtol</span> <span class="o">=</span> <span class="mf">1e-1</span>
<span class="lineno">83</span>        <span class="k">if</span> <span class="ow">not</span> <span class="n">torch</span><span class="o">.</span><span class="n">allclose</span><span class="p">(</span><span class="n">tri_dq</span><span class="p">,</span> <span class="n">ref_dq</span><span class="p">,</span> <span class="n">atol</span><span class="o">=</span><span class="mf">1e-2</span><span class="p">,</span> <span class="n">rtol</span><span class="o">=</span><span class="n">rtol</span><span class="p">):</span>
<span class="lineno">84</span>            <span class="n">abs_err</span><span class="p">,</span> <span class="n">rel_err</span> <span class="o">=</span> <span class="n">_calc_abs_rel_error</span><span class="p">(</span><span class="n">ref_dq</span><span class="p">,</span> <span class="n">tri_dq</span><span class="p">)</span>
<span class="lineno">85</span>            <span class="n">logger</span><span class="o">.</span><span class="n">log</span><span class="p">((</span><span class="s1">&#39;[FAILED]&#39;</span><span class="p">,</span> <span class="n">logger</span><span class="o">.</span><span class="n">Text</span><span class="o">.</span><span class="n">danger</span><span class="p">),</span> <span class="sa">f</span><span class="s1">&#39; dQ mismatch </span><span class="si">{</span><span class="n">abs_err</span><span class="si">}</span><span class="s1"> </span><span class="si">{</span><span class="n">rel_err</span><span class="si">}</span><span class="s1">&#39;</span><span class="p">)</span>
<span class="lineno">86</span>            <span class="n">passed</span> <span class="o">=</span> <span class="kc">False</span>
<span class="lineno">87</span>        <span class="k">if</span> <span class="ow">not</span> <span class="n">torch</span><span class="o">.</span><span class="n">allclose</span><span class="p">(</span><span class="n">tri_dv</span><span class="p">,</span> <span class="n">ref_dv</span><span class="p">,</span> <span class="n">atol</span><span class="o">=</span><span class="mf">1e-2</span><span class="p">,</span> <span class="n">rtol</span><span class="o">=</span><span class="n">rtol</span><span class="p">):</span>
<span class="lineno">88</span>            <span class="n">abs_err</span><span class="p">,</span> <span class="n">rel_err</span> <span class="o">=</span> <span class="n">_calc_abs_rel_error</span><span class="p">(</span><span class="n">ref_dv</span><span class="p">,</span> <span class="n">tri_dv</span><span class="p">)</span>
<span class="lineno">89</span>            <span class="n">logger</span><span class="o">.</span><span class="n">log</span><span class="p">((</span><span class="s1">&#39;[FAILED]&#39;</span><span class="p">,</span> <span class="n">logger</span><span class="o">.</span><span class="n">Text</span><span class="o">.</span><span class="n">danger</span><span class="p">),</span> <span class="sa">f</span><span class="s1">&#39; dV mismatch </span><span class="si">{</span><span class="n">abs_err</span><span class="si">}</span><span class="s1"> </span><span class="si">{</span><span class="n">rel_err</span><span class="si">}</span><span class="s1">&#39;</span><span class="p">)</span>
<span class="lineno">90</span>            <span class="n">passed</span> <span class="o">=</span> <span class="kc">False</span>
<span class="lineno">91</span>        <span class="k">if</span> <span class="ow">not</span> <span class="n">torch</span><span class="o">.</span><span class="n">allclose</span><span class="p">(</span><span class="n">tri_dk</span><span class="p">,</span> <span class="n">ref_dk</span><span class="p">,</span> <span class="n">atol</span><span class="o">=</span><span class="mf">1e-2</span><span class="p">,</span> <span class="n">rtol</span><span class="o">=</span><span class="n">rtol</span><span class="p">):</span>
<span class="lineno">92</span>            <span class="n">abs_err</span><span class="p">,</span> <span class="n">rel_err</span> <span class="o">=</span> <span class="n">_calc_abs_rel_error</span><span class="p">(</span><span class="n">ref_dk</span><span class="p">,</span> <span class="n">tri_dk</span><span class="p">)</span>
<span class="lineno">93</span>            <span class="n">logger</span><span class="o">.</span><span class="n">log</span><span class="p">((</span><span class="s1">&#39;[FAILED]&#39;</span><span class="p">,</span> <span class="n">logger</span><span class="o">.</span><span class="n">Text</span><span class="o">.</span><span class="n">danger</span><span class="p">),</span> <span class="sa">f</span><span class="s1">&#39; dK mismatch </span><span class="si">{</span><span class="n">abs_err</span><span class="si">}</span><span class="s1"> </span><span class="si">{</span><span class="n">rel_err</span><span class="si">}</span><span class="s1">&#39;</span><span class="p">)</span>
<span class="lineno">94</span>            <span class="n">passed</span> <span class="o">=</span> <span class="kc">False</span>
<span class="lineno">95</span>
<span class="lineno">96</span>        <span class="k">if</span> <span class="n">passed</span><span class="p">:</span>
<span class="lineno">97</span>            <span class="n">logger</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="s1">&#39;[PASSED]&#39;</span><span class="p">,</span> <span class="n">logger</span><span class="o">.</span><span class="n">Text</span><span class="o">.</span><span class="n">success</span><span class="p">)</span>
<span class="lineno">98</span>            <span class="n">s</span><span class="o">.</span><span class="n">success</span> <span class="o">=</span> <span class="kc">True</span>
<span class="lineno">99</span>        <span class="k">else</span><span class="p">:</span>
<span class="lineno">100</span>            <span class="n">s</span><span class="o">.</span><span class="n">success</span> <span class="o">=</span> <span class="kc">False</span>
<span class="lineno">101</span>        <span class="n">torch</span><span class="o">.</span><span class="n">cuda</span><span class="o">.</span><span class="n">synchronize</span><span class="p">()</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-7'>
        <div class='docs doc-strings'>
            <div class='section-link'>
                <a href='#section-7'>#</a>
            </div>
            <p> Get a partial function to test performance of our implementation</p>

        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">104</span><span class="k">def</span> <span class="nf">_perf_triton_fn</span><span class="p">(</span><span class="o">*</span><span class="p">,</span> <span class="n">device</span><span class="p">,</span> <span class="n">dtype</span><span class="p">,</span> <span class="n">batch_size</span><span class="p">,</span> <span class="n">k_heads</span><span class="p">,</span> <span class="n">n_groups</span><span class="p">,</span> <span class="n">seq_len</span><span class="p">,</span> <span class="n">d_head</span><span class="p">,</span> <span class="n">causal</span><span class="p">):</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-8'>
        <div class='docs'>
            <div class='section-link'>
                <a href='#section-8'>#</a>
            </div>
            
        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">108</span>    <span class="n">q</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">randn</span><span class="p">((</span><span class="n">batch_size</span><span class="p">,</span> <span class="n">k_heads</span> <span class="o">*</span> <span class="n">n_groups</span><span class="p">,</span> <span class="n">seq_len</span><span class="p">,</span> <span class="n">d_head</span><span class="p">),</span> <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">,</span> <span class="n">requires_grad</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="lineno">109</span>    <span class="n">k</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">randn</span><span class="p">((</span><span class="n">batch_size</span><span class="p">,</span> <span class="n">k_heads</span><span class="p">,</span> <span class="n">seq_len</span><span class="p">,</span> <span class="n">d_head</span><span class="p">),</span> <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">,</span> <span class="n">requires_grad</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="lineno">110</span>    <span class="n">v</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">randn</span><span class="p">((</span><span class="n">batch_size</span><span class="p">,</span> <span class="n">k_heads</span><span class="p">,</span> <span class="n">seq_len</span><span class="p">,</span> <span class="n">d_head</span><span class="p">),</span> <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">,</span> <span class="n">requires_grad</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="lineno">111</span>    <span class="n">sm_scale</span> <span class="o">=</span> <span class="n">d_head</span> <span class="o">**</span> <span class="o">-</span><span class="mf">0.5</span>
<span class="lineno">112</span>    <span class="k">return</span> <span class="k">lambda</span><span class="p">:</span> <span class="n">attention</span><span class="p">(</span><span class="n">q</span><span class="p">,</span> <span class="n">k</span><span class="p">,</span> <span class="n">v</span><span class="p">,</span> <span class="n">causal</span><span class="p">,</span> <span class="n">sm_scale</span><span class="p">)</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-9'>
        <div class='docs doc-strings'>
            <div class='section-link'>
                <a href='#section-9'>#</a>
            </div>
            <p> Get a partial function to test performance of original flash implementation</p>

        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">115</span><span class="k">def</span> <span class="nf">_perf_flash</span><span class="p">(</span><span class="o">*</span><span class="p">,</span> <span class="n">batch_size</span><span class="p">,</span> <span class="n">k_heads</span><span class="p">,</span> <span class="n">n_groups</span><span class="p">,</span> <span class="n">seq_len</span><span class="p">,</span> <span class="n">d_head</span><span class="p">,</span> <span class="n">causal</span><span class="p">,</span> <span class="n">device</span><span class="p">,</span> <span class="n">dtype</span><span class="p">):</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-10'>
        <div class='docs'>
            <div class='section-link'>
                <a href='#section-10'>#</a>
            </div>
            
        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">119</span>    <span class="n">q</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">randn</span><span class="p">((</span><span class="n">batch_size</span><span class="p">,</span> <span class="n">seq_len</span><span class="p">,</span> <span class="n">k_heads</span> <span class="o">*</span> <span class="n">n_groups</span><span class="p">,</span> <span class="n">d_head</span><span class="p">),</span> <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">,</span> <span class="n">requires_grad</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="lineno">120</span>    <span class="n">k</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">randn</span><span class="p">((</span><span class="n">batch_size</span><span class="p">,</span> <span class="n">seq_len</span><span class="p">,</span> <span class="n">k_heads</span><span class="p">,</span> <span class="n">d_head</span><span class="p">),</span> <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">,</span> <span class="n">requires_grad</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="lineno">121</span>    <span class="n">v</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">randn</span><span class="p">((</span><span class="n">batch_size</span><span class="p">,</span> <span class="n">seq_len</span><span class="p">,</span> <span class="n">k_heads</span><span class="p">,</span> <span class="n">d_head</span><span class="p">),</span> <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">,</span> <span class="n">requires_grad</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="lineno">122</span>    <span class="kn">from</span> <span class="nn">flash_attn</span> <span class="kn">import</span> <span class="n">flash_attn_func</span>
<span class="lineno">123</span>    <span class="k">return</span> <span class="k">lambda</span><span class="p">:</span> <span class="n">flash_attn_func</span><span class="p">(</span><span class="n">q</span><span class="p">,</span> <span class="n">k</span><span class="p">,</span> <span class="n">v</span><span class="p">,</span> <span class="n">causal</span><span class="o">=</span><span class="n">causal</span><span class="p">)</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-11'>
        <div class='docs doc-strings'>
            <div class='section-link'>
                <a href='#section-11'>#</a>
            </div>
            <h3>Measure the speed</h3>

        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">126</span><span class="k">def</span> <span class="nf">measure_performance</span><span class="p">(</span><span class="n">name</span><span class="p">,</span> <span class="n">fn</span><span class="p">,</span> <span class="o">*</span><span class="p">,</span> <span class="n">batch_size</span><span class="p">,</span> <span class="n">k_heads</span><span class="p">,</span> <span class="n">n_groups</span><span class="p">,</span> <span class="n">seq_len</span><span class="p">,</span> <span class="n">d_head</span><span class="p">,</span> <span class="n">causal</span><span class="p">,</span> <span class="n">is_bwd</span><span class="p">:</span> <span class="nb">bool</span><span class="p">):</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-12'>
        <div class='docs'>
            <div class='section-link'>
                <a href='#section-12'>#</a>
            </div>
            
        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">130</span>    <span class="k">if</span> <span class="n">is_bwd</span><span class="p">:</span>
<span class="lineno">131</span>        <span class="n">o</span> <span class="o">=</span> <span class="n">fn</span><span class="p">()</span>
<span class="lineno">132</span>        <span class="n">do</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">randn_like</span><span class="p">(</span><span class="n">o</span><span class="p">)</span>
<span class="lineno">133</span>        <span class="n">fn</span> <span class="o">=</span> <span class="k">lambda</span><span class="p">:</span> <span class="n">o</span><span class="o">.</span><span class="n">backward</span><span class="p">(</span><span class="n">do</span><span class="p">,</span> <span class="n">retain_graph</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="lineno">134</span>    <span class="n">ms</span> <span class="o">=</span> <span class="n">triton</span><span class="o">.</span><span class="n">testing</span><span class="o">.</span><span class="n">do_bench</span><span class="p">(</span><span class="n">fn</span><span class="p">)</span>
<span class="lineno">135</span>
<span class="lineno">136</span>    <span class="n">flops_per_matmul</span> <span class="o">=</span> <span class="mf">2.0</span> <span class="o">*</span> <span class="n">batch_size</span> <span class="o">*</span> <span class="n">k_heads</span> <span class="o">*</span> <span class="n">n_groups</span> <span class="o">*</span> <span class="n">seq_len</span> <span class="o">*</span> <span class="n">seq_len</span> <span class="o">*</span> <span class="n">d_head</span>
<span class="lineno">137</span>    <span class="n">total_flops</span> <span class="o">=</span> <span class="mi">2</span> <span class="o">*</span> <span class="n">flops_per_matmul</span>
<span class="lineno">138</span>    <span class="k">if</span> <span class="n">causal</span><span class="p">:</span>
<span class="lineno">139</span>        <span class="n">total_flops</span> <span class="o">*=</span> <span class="mf">0.5</span>
<span class="lineno">140</span>    <span class="k">if</span> <span class="n">is_bwd</span><span class="p">:</span>
<span class="lineno">141</span>        <span class="n">total_flops</span> <span class="o">*=</span> <span class="mf">2.5</span>  <span class="c1"># 2.0(bwd) + 0.5(recompute)</span>
<span class="lineno">142</span>
<span class="lineno">143</span>    <span class="n">tf_ps</span> <span class="o">=</span> <span class="n">total_flops</span> <span class="o">*</span> <span class="mf">1e-12</span> <span class="o">/</span> <span class="p">(</span><span class="n">ms</span> <span class="o">*</span> <span class="mf">1e-3</span><span class="p">)</span>
<span class="lineno">144</span>    <span class="n">logger</span><span class="o">.</span><span class="n">log</span><span class="p">((</span><span class="sa">f</span><span class="s1">&#39;</span><span class="si">{</span><span class="n">name</span><span class="si">}</span><span class="s1">&#39;</span><span class="p">,</span> <span class="n">logger</span><span class="o">.</span><span class="n">Text</span><span class="o">.</span><span class="n">key</span><span class="p">),</span> <span class="s1">&#39;: &#39;</span><span class="p">,</span> <span class="sa">f</span><span class="s1">&#39;</span><span class="si">{</span><span class="n">ms</span><span class="w"> </span><span class="si">:</span><span class="s1">,.1f</span><span class="si">}</span><span class="s1">ms&#39;</span><span class="p">,</span> <span class="s1">&#39; &#39;</span><span class="p">,</span> <span class="sa">f</span><span class="s1">&#39;</span><span class="si">{</span><span class="n">tf_ps</span><span class="w"> </span><span class="si">:</span><span class="s1">,.2f</span><span class="si">}</span><span class="s1">TFps&#39;</span><span class="p">)</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-13'>
        <div class='docs'>
            <div class='section-link'>
                <a href='#section-13'>#</a>
            </div>
            
        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">147</span><span class="k">def</span> <span class="nf">main</span><span class="p">():</span>
<span class="lineno">148</span>    <span class="n">device</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">device</span><span class="p">(</span><span class="s1">&#39;cuda:0&#39;</span><span class="p">)</span>
<span class="lineno">149</span>    <span class="n">torch</span><span class="o">.</span><span class="n">cuda</span><span class="o">.</span><span class="n">set_device</span><span class="p">(</span><span class="n">device</span><span class="p">)</span>
<span class="lineno">150</span>
<span class="lineno">151</span>    <span class="n">dtype</span> <span class="o">=</span> <span class="n">torch</span><span class="o">.</span><span class="n">float16</span></pre></div>
        </div>
    </div>
    <div class='section' id='section-14'>
        <div class='docs'>
            <div class='section-link'>
                <a href='#section-14'>#</a>
            </div>
            <p>only works on post-Ampere GPUs right now </p>

        </div>
        <div class='code'>
            <div class="highlight"><pre><span class="lineno">154</span>    <span class="n">test_fwd_bwd</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="mi">4</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">2048</span><span class="p">,</span> <span class="mi">2048</span><span class="p">,</span> <span class="mi">128</span><span class="p">,</span> <span class="kc">True</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">)</span>
<span class="lineno">155</span>    <span class="n">test_fwd_bwd</span><span class="p">(</span><span class="mi">16</span><span class="p">,</span> <span class="mi">32</span><span class="p">,</span> <span class="mi">8</span><span class="p">,</span> <span class="mi">2001</span><span class="p">,</span> <span class="mi">4001</span><span class="p">,</span> <span class="mi">128</span><span class="p">,</span> <span class="kc">False</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">)</span>
<span class="lineno">156</span>    <span class="n">test_fwd_bwd</span><span class="p">(</span><span class="mi">4</span><span class="p">,</span> <span class="mi">32</span><span class="p">,</span> <span class="mi">8</span><span class="p">,</span> <span class="mi">2048</span><span class="p">,</span> <span class="mi">1024</span><span class="p">,</span> <span class="mi">128</span><span class="p">,</span> <span class="kc">False</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">)</span>
<span class="lineno">157</span>    <span class="n">test_fwd_bwd</span><span class="p">(</span><span class="mi">4</span><span class="p">,</span> <span class="mi">32</span><span class="p">,</span> <span class="mi">8</span><span class="p">,</span> <span class="mi">2001</span><span class="p">,</span> <span class="mi">4001</span><span class="p">,</span> <span class="mi">128</span><span class="p">,</span> <span class="kc">True</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">)</span>
<span class="lineno">158</span>
<span class="lineno">159</span>    <span class="n">_conf</span> <span class="o">=</span> <span class="p">{</span>
<span class="lineno">160</span>        <span class="s1">&#39;batch_size&#39;</span><span class="p">:</span> <span class="mi">16</span><span class="p">,</span>
<span class="lineno">161</span>        <span class="s1">&#39;k_heads&#39;</span><span class="p">:</span> <span class="mi">8</span><span class="p">,</span>
<span class="lineno">162</span>        <span class="s1">&#39;n_groups&#39;</span><span class="p">:</span> <span class="mi">4</span><span class="p">,</span>
<span class="lineno">163</span>        <span class="s1">&#39;seq_len&#39;</span><span class="p">:</span> <span class="mi">2048</span><span class="p">,</span>
<span class="lineno">164</span>        <span class="s1">&#39;d_head&#39;</span><span class="p">:</span> <span class="mi">128</span><span class="p">,</span>
<span class="lineno">165</span>    <span class="p">}</span>
<span class="lineno">166</span>
<span class="lineno">167</span>    <span class="k">for</span> <span class="n">_causal</span> <span class="ow">in</span> <span class="p">[</span><span class="kc">False</span><span class="p">,</span> <span class="kc">True</span><span class="p">]:</span>
<span class="lineno">168</span>        <span class="k">for</span> <span class="n">is_bwd</span> <span class="ow">in</span> <span class="p">[</span><span class="kc">False</span><span class="p">,</span> <span class="kc">True</span><span class="p">]:</span>
<span class="lineno">169</span>            <span class="n">logger</span><span class="o">.</span><span class="n">log</span><span class="p">(</span><span class="sa">f</span><span class="s1">&#39;</span><span class="si">{</span><span class="s2">&quot;Causal&quot;</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="n">_causal</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="s2">&quot;Non-causal&quot;</span><span class="si">}</span><span class="s1"> </span><span class="si">{</span><span class="s2">&quot; Backward&quot;</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="n">is_bwd</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="s2">&quot;&quot;</span><span class="si">}</span><span class="s1">&#39;</span><span class="p">,</span> <span class="n">logger</span><span class="o">.</span><span class="n">Text</span><span class="o">.</span><span class="n">title</span><span class="p">)</span>
<span class="lineno">170</span>            <span class="n">measure_performance</span><span class="p">(</span><span class="sa">f</span><span class="s1">&#39;flash&#39;</span><span class="p">,</span> <span class="n">_perf_flash</span><span class="p">(</span><span class="n">causal</span><span class="o">=</span><span class="n">_causal</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="o">**</span><span class="n">_conf</span><span class="p">),</span>
<span class="lineno">171</span>                                <span class="n">is_bwd</span><span class="o">=</span><span class="n">is_bwd</span><span class="p">,</span>
<span class="lineno">172</span>                                <span class="n">causal</span><span class="o">=</span><span class="n">_causal</span><span class="p">,</span> <span class="o">**</span><span class="n">_conf</span><span class="p">)</span>
<span class="lineno">173</span>            <span class="n">measure_performance</span><span class="p">(</span><span class="sa">f</span><span class="s1">&#39;triton&#39;</span><span class="p">,</span> <span class="n">_perf_triton_fn</span><span class="p">(</span><span class="n">causal</span><span class="o">=</span><span class="n">_causal</span><span class="p">,</span> <span class="n">device</span><span class="o">=</span><span class="n">device</span><span class="p">,</span> <span class="n">dtype</span><span class="o">=</span><span class="n">dtype</span><span class="p">,</span> <span class="o">**</span><span class="n">_conf</span><span class="p">),</span>
<span class="lineno">174</span>                                <span class="n">is_bwd</span><span class="o">=</span><span class="n">is_bwd</span><span class="p">,</span>
<span class="lineno">175</span>                                <span class="n">causal</span><span class="o">=</span><span class="n">_causal</span><span class="p">,</span> <span class="o">**</span><span class="n">_conf</span><span class="p">)</span>
<span class="lineno">176</span>
<span class="lineno">177</span>
<span class="lineno">178</span><span class="k">if</span> <span class="vm">__name__</span> <span class="o">==</span> <span class="s2">&quot;__main__&quot;</span><span class="p">:</span>
<span class="lineno">179</span>    <span class="n">main</span><span class="p">()</span></pre></div>
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